Tensioning device for shuttles



Jan. 19, 1937.

J. B. PLEVYAK TENsIoNING DEVICE FOR sHUTTLEs Filed Feb. l1, 1936' Patented Jan. 19, 1937 UNITED STATES-f PATENT OFFICE 4 Claims.

My invention relates to tensioning devices for weavers shuttles, and is specially adapted for use in the weaving of silk cloth which is formed of very'ne silk strands.

'In weaving this kind of cloth .it is very important 'that the thread be fed out from the shuttle with an even tension in order to produce a smooth weave Awithout which the glossy sheen, often so much Idesired in this kind of cloth, cannot be imparted to it.

In order to give an even tension to the threads, as they are laid across the cloth from selvedge to selvedge, it is absolutely necessary that .the spring or yielding member which controls the tension arm should have a wide range of yielding capacity so as to impart to the thread a practically even tensionthroughout the entire thrust of the shuttle.

The general objects and aims sought to be accomplished by the present invention are the same as those set forth in my Patent No. 2,002,866, dated May *28, 1935; but the present invention provides a much simpler and less expensive mechanism for producing the same results sought by the previous invention, and gives a device which is much ymore easily installed inthe shuttle with which it is to be used, and which is much more easily manipulated.

A further special object of the present invention is to provide simple means whereby one tension'ing arm can be replaced by another with the yutmost ease, and in a moment of time, without removing or altering the position of any of the other parts of the device.

Minor objects will appear in the subjoined description.

A leading feature of the invention consists of an adjustable ring screw with a double torsion 'spring mounted thereon, the two sections of the spring being connected by a comparatively long U-shaped loop projecting to one side of the ringscrew, and a tension arm having at its inner end a clip arrangement adapted for snap-engagement with the ringscrew in the space between the two sides of the U-shaped loop of the double torsion spring, with `the shank of said tension arm projecting outwardly from the ring screw across the upper side of the bend in the U-shaped loop of the double tension spring.

The invention consists in certain novel features of construction and arrangement of parts, as will be hereinafter described and claimed, refence being had to the accompanying drawing in which:-

Fig. l is a top plan view of the ring screw of my device. Fig. 2 is a side elevation of the ring screw .with the tension spring mounted thereon. Fig. 13 is a side elevation of one form of the tension spring. Fig. 4 is a slightly modied form of vtension spring. Fig. 5 is a bottom plan view of Fig. 3. Fig. 6 is a side elevation, on a reduced scale, of .the tension screw. Figs. 7 and 8 are top and bottom plan views respectively of Fig. 4. Fig. 9 is a side elevation of the tension arm. Fig. l0 is a top plan view of the forward end of a shuttle, showing my device in operative position therein; and, Fig. ll is a broken side elevation, on an enlarged scale, showing a slightly modified clip at the inner end of the Vtension arm.

Referring further to the drawing, the numeral I indicates the tension screw as a Whole, and the numeral 2 they tension spring. The tension screw I comprises a head la, a shank portion AIb terminating at its lower end in a threaded por- 'The'head la of the tension screw is prothreaded lower end lo of the set screw is provided with a slot 15,.

The tension .spring 2 is a torsion spring designed to encircle vthe tension screw, and .has `for its central portion a loop or U-shaped section which projects to one .side of said tension screw.

Integrally formed with said U-shaped ksection is the upper portion 2a.` of the spring, and the lower portion 2b. Said upper portion 2a terminates at its extreme upper end in a vertical section 6; and the lower portion 2bv terminates at its extreme end in an inwardly extending horizontal Vsection l, (see Fig. 5).

In the slightly modied Iform of tension spring shown in Fig. 4, the upper and lower coils 2017 and 2bn of the spring are of the same diameter as are the corresponding coils in the sections 2a vand `2b respectively of the spring shown in Fig. 3,

lbut the coils of each section gradually increase in diameter going outwardly from the U-shaped section 2am at the middle of the spring till the end coils of each section are reached, which latter, as yalready stated, are of greater diameter than thecoils next to the U-shaped section.

It is apparent at a glance that it requires a greater length of wire to form the spring illustrated in Fig. 4 than the spring illustrated in Fig. 3, and for that reason, the spring illustrated in Fig. 4 has a greater range of yielding movement than does the spring illustrated in Fig. '3.

In Fig. 9 I have illustrated my improved tension arm 8 which has two features to which special attention is called. First, the inner end of this arm is formed into a snap-clip 9 provided at its upper end with two complementary curved portions 9a and 9b, which t around the shank Ib of the adjusting screw, so as to permit the arm 8 to rotate on said shank Ib. In other words, by this arrangement, the adjusting screw forms a pivot upon which the tension arm is rotatably mounted. The snap-clip 9 is elongated downwardly, and at its lower end may be provided with an integral spring coil I0 which serves to give the clip greater resiliency. But in cases where this greater resiliency is not desired, the coil at the lower end of the clip may be omitted, as is illustrated at I Ua. in Fig. 11.

'I'he second feature of the tension arm, to which special attention is called, is the way in which its coils I2 are formed. From Figs. 9 and l0 it will be seen that the upper portion I2a of each coil is disposed substantially in a somewhat vertical plane at right angles to the longitudinal extent of the tension arm, while the lower part I2b of each of said coils is 'disposed in a somewhat vertical plane extending at an angle to both the longitudinal and transverse extent of the tension arm, as is more clearly shown in Fig. 10, in which the lower half I2b of each coil is shown as disposed in a somewhat vertical plane extending at approximately 45 to the longitudinal extent of the tension arm: or, in other words, the plane of the lower part of each coil is disposed at about an equal angle to both the longitudinal and transverse extent of the tension arm, while the upper part of each coil is always in a somewhat vertical plane extending transversely of the longitudinal extent of said tension arm. By forming the tension arm in this way, there are no short and abrupt bends in the Wire of which it is made, while in the ordinary tension arm, the short and tight abrupt bends often break the wire, and at best are somewhat diiicult to make.

'Ihe upper transverse sections I2a. of the coils are substantially parallel with the tension bars I3 of the shuttle, and are arranged to project upwardly midway between said bars I3.

These two special features, just above referred to, in the construction of my tension arm make it decidedly superior to the tension arm now in common use in shuttles.

The operation of my device is exceedingly simple. The tension spring is placed in the position shown in the opening :v of the shuttle,

as shown in Fig. 10, and the tension screw is passed through a bore I4 in the side wall of the shuttle, said bore being of a size to snugly receive the head Ia. of the tension spring. The shank Ib of the tension screw is passed through the central opening of the tension spring, with the lower extremity 1 of the spring (see Fig. 5) received into the slot 5 at the lower end of the tension screw, and with the upper extremity 6 of the spring received into the longitudinal slot 4 of the tension screw head Ia, as is clearly illustrated in Fig. 2 of the drawing. 'I'he tension screw, upon which the spring 2 is mounted, is then rotated with a screw driver (entered in the transverse slot 3) to cause the lower threaded end-section Ic of the screw to take into a suitable opening in the wall of the shuttle, at the left side of the opening all as clearly illustrated in Fig. l0. When the tension screw is thus iirmly anchored in the shuttle, the inner end oi the tension arm is entered in the space I5 between the two parallel sides of the U- shaped loop 2am of the tension spring, and is snapped onto the tension screw, with the shank of the tension arm resting on top of the bent outer end of the U-shaped loop of the tension spring.

When thus arranged it is manifest that the tension on the tension arm can be increased or diminished by simply rotating the tension screw to the right or to the left, as the case may require.

When it is desired that the tension arm may have the greatest possible range of movement, the form of spring shown in Fig. 4, may be used. By which arrangement the variation in the tension upon the tension arm will be so slight in all the different positions of the tension arm, that there will be no jerking of the thread as the shuttle is thrust forward, but on the contrary, the unwinding-pull on the thread will be so even and regular that the shuttle will not have to be provided on its inside with fur, as is common in ordinary shuttles.

From the foregoing it will be seen that I have provided a tensioning device of great simplicity, and one that is very eiective in its operation, being extremely easy to adjust, and one in which the tensioning arm may be inserted or removed with the utmost ease and facility.

Having described my invention, what I claim as new and 'desire to protect by Letters Patent is:-

1. In tensioning devices for shuttles, a tension screw; a torsion spring mounted thereon between the ends thereof, with an integral portion of the centre of the spring projecting to one side of the spring and screw; means for holding the two ends of said spring in fixed relation to the screw, whereby the projecting central portion of the spring is yieldingly supported on the screw to rotate therewith; and a tension arm rotatably mounted at its inner end on the tension screw adjacent said projecting central portion of the spring, and extending beyond said portion in the same direction therewith, said arm being arranged to be engaged between its ends by the outer end of said projecting portion of the spring, whereby the spring yieldingly resists the free movement of said arm.

2. A tensioning 4device for shuttles, comprising a` tension screw, and a torsion spring mounted thereon between the ends thereof, with an integral U-shaped portion at the centre of the spring projecting to one side of the spring and screw, said U-shaped portion dividing the torsion spring into two equal parts, one composed of right hand coils and the other of left hand coils; means for holding the extreme ends of said torsion spring in xed relation to the screw, whereby when the screw is rotated, the entire spring, including the projecting U-shaped loop portion at the centre, will be rotated with the screw; and a tension arm rotatably mounted at its inner end on the tension screw between the two legs of the U- shaped loop and extending beyond the loop lapping the curved bottom of the same on the upper side thereof, whereby the bottom of the U-shaped loop forms a yielding fulcrum for the tension arm.

3. The combination with a shuttle having an opening therein, with opposing side walls, of a transverse tension screw having a head portion at one end and a threaded portion at the other end, said head portion having a longitudinal slot .in one side thereof, and said threaded portion having a diametrical slot therein, the head portion of the screw being designed to be anchored in one of said opposing side walls, and the threaded portion in the other; a torsion spring mounted on said screw between its head portion and its threaded portion and having at its centre an integral U-shaped portion projecting to one side of the spring and screw, said spring terminating at one end in a section adapted to be received into said longitudinal slot in the head of the screw, and at its other end terminating in a section adapted to be received into said diametrical slot in the threaded end of the screw, whereby to hold the spring at both ends against rotatable movement on the tensiori screw, and whereby, when the tension screw is rotated, the entire spring, including the projecting U-shaped portion at the centre, will be rotated with the screw; and a tension arm rotatably mounted at its inner end on the tension screw at the middle of the spring and of said opening in the shuttle, and between the two legs of the U-shaped loop of the spring, and extending on beyond the loop crossing the bottom section thereof; whereby the bottom section of the loop forms a yielding and an adjustable fulcrum for the tension arm.

4. In tensioning devices for shuttles, a tension screw; a torsion spring mounted thereon between the ends thereof, with an integral portion of the centre of the spring projecting to one side of the spring and screw; means for holding the two ends of saidl spring in fixed relation to the screw, whereby the projecting central portion of the spring is yeldingly supported on the screw to rotate therewith; and a tension arm rotatably mounted at its inner end on the tension screw adjacent said projecting central portion of the spring, and extending beyond said portion in the same direction therewith, said arm being adapted at its inner end for snap engagement with the ring, and operatively engaged between its ends by said projecting portion of the spring, whereby the spring yieldingly resists the free movement of said arm.

JOSEPH B. PLEVYAK. 

